bat/src/diff.rs
Aleksey Kladov 35347c2310 Improve readability
Using `Path`s for paths expresses intent more clearly.
2021-03-07 14:59:10 +01:00

84 lines
2.4 KiB
Rust

#![cfg(feature = "git")]
use std::collections::HashMap;
use std::fs;
use std::path::Path;
use git2::{DiffOptions, IntoCString, Repository};
#[derive(Copy, Clone, Debug)]
pub enum LineChange {
Added,
RemovedAbove,
RemovedBelow,
Modified,
}
pub type LineChanges = HashMap<u32, LineChange>;
pub fn get_git_diff(filename: &Path) -> Option<LineChanges> {
let repo = Repository::discover(&filename).ok()?;
let repo_path_absolute = fs::canonicalize(repo.workdir()?).ok()?;
let filepath_absolute = fs::canonicalize(&filename).ok()?;
let filepath_relative_to_repo = filepath_absolute.strip_prefix(&repo_path_absolute).ok()?;
let mut diff_options = DiffOptions::new();
let pathspec = filepath_relative_to_repo.into_c_string().ok()?;
diff_options.pathspec(pathspec);
diff_options.context_lines(0);
let diff = repo
.diff_index_to_workdir(None, Some(&mut diff_options))
.ok()?;
let mut line_changes: LineChanges = HashMap::new();
let mark_section =
|line_changes: &mut LineChanges, start: u32, end: i32, change: LineChange| {
for line in start..=end as u32 {
line_changes.insert(line, change);
}
};
let _ = diff.foreach(
&mut |_, _| true,
None,
Some(&mut |delta, hunk| {
let path = delta.new_file().path().unwrap_or_else(|| Path::new(""));
if filepath_relative_to_repo != path {
return false;
}
let old_lines = hunk.old_lines();
let new_start = hunk.new_start();
let new_lines = hunk.new_lines();
let new_end = (new_start + new_lines) as i32 - 1;
if old_lines == 0 && new_lines > 0 {
mark_section(&mut line_changes, new_start, new_end, LineChange::Added);
} else if new_lines == 0 && old_lines > 0 {
if new_start == 0 {
mark_section(&mut line_changes, 1, 1, LineChange::RemovedAbove);
} else {
mark_section(
&mut line_changes,
new_start,
new_start as i32,
LineChange::RemovedBelow,
);
}
} else {
mark_section(&mut line_changes, new_start, new_end, LineChange::Modified);
}
true
}),
None,
);
Some(line_changes)
}